STILLWATER, Okla. (AP) — Baylor arrived at Oklahoma State seeking its first win in Stillwater since 1939 — and a statement win to validate its case as a national championship contender.

The No. 3 Bears failed in stunning fashion, falling 49-17 in a crushing loss to the No. 11 Cowboys on Saturday night and sending another shockwave through the top of the BCS standings.

The loss for Baylor (9-1, 6-1 Big 12 Conference) almost certainly dooms its national title aspirations, leaving Alabama, Florida State and Ohio State as the remaining unbeatens near the top of the BCS standings. They’ll certainly line up in that order when the new numbers come out Sunday, with the Bears likely no longer in the picture.

Bryce Petty was 28 of 48 passing for 359 yards for Baylor, which had its school-record 13-game winning streak snapped in convincing fashion.

“This is very difficult,” Baylor safety Ahmad Dixon said. “… This hurts. Our chances of still winning the Big 12 aren’t over, but we wanted something bigger than that.

“We wanted something that’s never been done before, and that was to go to a national championship. That dream came down.”

The Bears were done in thanks to Oklahoma State quarterback Clint Chelf’s latest career day against them, a performance that put the Cowboys (10-1, 7-1) within reach of a Big 12 championship.

Chelf passed for a career-high 370 yards and accounted for four touchdowns Saturday. He was 19 of 25 passing and has now thrown for 703 yards in his last two games against Baylor — including last year’s 41-34 loss in Waco.

His latest performance came in a win, a crushing one that delighted the record crowd of 60,218 in Boone Pickens Stadium.

“I couldn’t be more proud of what he’s accomplished,” Oklahoma State coach Mike Gundy said. “He’s been a good leader and he does it quiet. He’s been humbled, and for that he’s had success.”

Oklahoma State has won 10 or more games in three of the last four seasons, and can win the Big 12 by beating rival Oklahoma at home in two weeks.

If Chelf, who lost the starting job earlier this season for the Cowboys, plays like he did on Saturday night against the Sooners, a win is certainly possible.

The senior threw three touchdown passes and ran for a score against the Bears, topping the career day he had against them last year with 333 yards passing. He also had a 48-yard reception and finished with 438 yards of total offense.

Tracy Moore finished with five catches for 126 for Oklahoma State.

While the Cowboys had 594 yards of total offense, it was the usually high-flying Bears who were grounded.

Baylor entered Saturday averaging a national-best 61.2 points and 684.8 yards per game, but they had no answers for a Cowboys’ defense that held the high-powered attack in check most of the way.

Oklahoma State forced three Baylor fumbles and also stopped the Bears on two key fourth-down attempts in the second half — both of which led to Cowboys’ touchdowns.

Baylor finished with 453 yards of total offense, and Antwan Goodley had 10 catches for 118 yards receiving.

“(Oklahoma State) played extremely well, played with a lot of energy, made plays when they needed to make plays,” Baylor coach Art Briles said.

After falling behind 35-3, Baylor appeared on the verge of cutting the lead to 35-17 early in the fourth quarter.

However, Petty fumbled after a wild snap deep in Oklahoma State territory and Tyler Patmon returned it 78 yards for a touchdown to put the Cowboys up 42-10.

The score put the exclamation point on a thoroughly one-sided performance.

Chelf lost the starting job earlier this year to sophomore J.W. Walsh, and the senior slowly worked his way back to the role of top option for the Cowboys. He accounted for four touchdowns in last week’s win overTexas, but was at his best Saturday night — capping the stunning performance with a 33-yard touchdown pass to Jhajuan Seales.

As has been the case for most of the season, Gundy didn’t make Chelf available to talk following Saturday’s win. His coach, however, had plenty to say about his recent performances.

“I’m happy with the groove he’s in right now,” Gundy said. “And so, we just want to let him keep going.”

Baylor appeared on its way to the early lead when Petty broke free on a third-and-2 on the Bears’ second possession — with no defenders in his path to the end zone.

However, the quarterback — who entered the game leading the Big 12 in total offense — tripped short of the end zone and fell down at the Oklahoma State 1. Two plays later, Shock Linwood fumbled when he tried to stretch out for the touchdown — with James Castleman knocking the ball loose and recovering for the Cowboys.

That was followed by a 99-yard touchdown drive for Oklahoma State. Kye Staley capped the quick turn of momentum with a 2-yard touchdown run to put the Cowboys up 7-0, a drive that included a 51-yard pass from Chelf to Marcell Ateman.

Oklahoma State pushed its lead to 14-0 in the second quarter when Chelf found Charlie Moore for a 12-yard touchdown over the middle. The completion was Chelf’s 11th-straight of the game.

Chelf didn’t have an incompletion until Oklahoma State’s final possession of the first half, and he finished the half 12 of 13 passing for 238 yards.

“He’s a leader,” Oklahoma State wide receiver Josh Stewart said. “That’s what we want from our quarterback, and he gives us everything we need.”

The Cowboys held Baylor to three three-and-outs on seven possessions in the first half. The Bears entered the game having been held to 17 three-and-outs all season, and their three points at halftime was their lowest first-half total since being held scoreless by Oklahoma State in 2011.

“We’ll bounce back from this,” Petty said. “I’m not going anywhere, and we’re not going anywhere. We still have a lot to accomplish.”

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